Actas de congresos
Flow hydrodynamics and contaminant transport in the flow past a lateral square cavity
Fecha
2015Institución
Resumen
Turbulent flows past lateral cavities play an important
role in the transport of contaminants in rivers and streams. Cavities are surface
storage zones, where large-scale unsteady coherent structures are the leading mechanisms
that produce longer residence times and control the fate of contaminants in
the river. In this work we study the recirculating flow and mass transport in a lateral
square cavity, by performing numerical simulations with a hybrid URANS/LES
turbulence model (DES-LR). We focus on the dynamics of the coherent structures
and their impacts on the transport and storage of a passive scalar. In addition, we
use the numerical results to develop new 1D models that improve the description
of the evolution of the averaged concentration inside the cavity. By transferring
the information to larger spatial scales, we provide new insights on the mechanisms
of contaminant transport and analyze the overall effects of surface storage zones in
open channel flows.